1. Field
The present embodiments relate to a secondary battery.
2. Description of the Related Art
Portable electric/electronic devices have a battery pack to be operated in any place where a power source is not separately available. The battery pack employs rechargeable secondary batteries in an economical aspect.
Examples of the secondary battery include nickel-cadmium (Ni—Cd), nickel-metal hydride (Ni-MH), lithium (Li) batteries, and lithium ion batteries. Among them, the Li secondary batteries are widely used for portable electric-electronic devices because of a five times higher operating voltage and a higher energy density per unit weight than the Ni—Cd or Ni-MH batteries.
Secondary batteries are manufactured in various shapes such as a cylindrical shape, a prismatic shape and a pouch shape.
In addition, secondary batteries are used with a protective circuit module connected to a battery cell in view of safety. The protective circuit module is used in the secondary battery such that a printed circuit pattern is formed on an insulating substrate, and a plurality of electric devices and a protection circuit, are attached to the printed circuit pattern.
However, a portion of the protective circuit module should be cut out to enable welding of a cell tab of the battery cell.